Within the framework of the original Program Project application consisting of 3 projects and 3 cores, progress was made during the past four years in cutaneous basement membrane zone (BMZ) studies and in developing ex vivo gene therapy for epidermolysis bullosa (EB). BMZ studies have helped to elucidate the role of BMZ proteins in epidermal adhesion, healing, cell migration, neoplasia and EB. Ex vivo gene therapy efforts have also met with some success and provide the basis for human clinical trials now being initiated in EB. This progress has laid the foundation for efforts to develop the next level of advances in molecular therapeutics for direct administration to skin in the context of further biological studies directed at epidermal BMZ biology and carcinogenesis. This focus on direct tissue delivery is designed to generate more practical therapeutic technology platforms for future application in humans. The specific goals of this research proposal are 1) to develop new approaches for delivery of gene and protein-based molecular therapeutics to skin, 2) to define further the mechanistic basis for BMZ changes in epidermal neoplasia and to identify targets for its regulation, 3) to characterize and develop a new general approach for molecular therapy to epithelium via non viral integrating vectors and 4) to characterize signaling pathway elements in epidermal carcinogenesis and identify therapeutic targets for their disruption. The specific projects are as follows: 1. Delivery of Molecular Therapeutics to Skin (P.A. Khavari)2. Epithelial Matrix as a Target for Molecular Therapy (M.P. Marinkovich) 3. Transposon Based Gene Therapeutics (M.A. Kay)4. Signaling and Therapeutic Targeting in Epidermal Neoplasia (A.E. Oro) The central objective of this proposal, framed within the context of increasing insight into epidermal BMZ function in genodermatoses and neoplasia, is the development of new molecular therapeutic approaches for 2 representative diseases affecting these processes, epidermolysis bullosa and epidermal cancer.